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Exhaust silencer diameter Q
J666AYP - 21/3/21 at 11:24 PM

Hi all,

Just in the process of ordering the exhaust silencer and gubbins for finishing the exhaust system off. Just wondering if I would be better off with a 6" or 7" diameter silencer? (3" bore and 18" long).

Thanks,
J

ianhurley20 - 22/3/21 at 08:38 AM

I simply went for the biggest straight through silencer I could fit - 24" x 7" 52mm bore - car sounded great, only got noisy when on full throttle but a lovely noise the rest of the time and 5db below legal limit at IVA

big_wasa - 22/3/21 at 11:34 AM

6x20 with a 2.5" bore on mine its a very quiet with the turbo and a cat.

simon04 - 22/3/21 at 09:10 PM

turbo motors are normally quieter than Nas.

6 inch is a good big size and about 600 to 700 long

Repackable if poss

HAve a look at tiger ot striker or the other big boys like westfield and caterham

J666AYP - 23/3/21 at 08:21 PM

Thanks for the input gents, appreciated.

Just to confirm does a 'Q' plate need a cat for the IVA? Seem to be getting conflicting information online?

J

obfripper - 23/3/21 at 08:51 PM

quote:
Originally posted by J666AYP
Thanks for the input gents, appreciated.

Just to confirm does a 'Q' plate need a cat for the IVA? Seem to be getting conflicting information online?

J


For the iva you'll need to pass the test applicable for your engine, that should be a cat emissions test for your merc engine unless it's pre aug 1994 which i guess is unlikely.
As the donor was capable of passing a cat test, so long as you have a reasonable size/quality cat fitted there shouldn't be a problem, the original one being the best option if you still have it.

Once iva is done, if you're on a 'q' plate, then for mot you will only require a visual check.

Dave

J666AYP - 23/3/21 at 11:46 PM

Thanks Dave,

Thats cleared up the confusion for me

J